EFFECT OF ORAL CREATINE SUPPLEMENTATION ON RESPIRATORY GAS-EXCHANGE AND BLOOD LACTATE ACCUMULATION DURING STEADY-STATE INCREMENTAL TREADMILL EXERCISE AND RECOVERY IN MAN

1. Oral creatine supplementation has been shown to increase muscle cre atine and phosphocreatine concentrations with consequent benefits on p erformance during short-term maximal exercise. However, recently there have been anecdotal reports that creatine supplementation can also in fluence the pattern of substrate utilization and improve performance d uring more prolonged, submaximal exercise, which, based on recent expe rimental evidence, may have some scientific justification. 2. Eight me n performed a continuous incremental exercise test running at 10 km/h on a motorized treadmill at predetermined workloads from 50% to 90% of maximal oxygen uptake, before and after 5 days of creatine supplement ation (4 x 5 g daily). Exercise was performed for 6 min at each worklo ad to achieve a steady state, and respiratory gas exchange and blood l actate concentrations were measured during the last 30 s at each workl oad, Measurements were also made at 5-min intervals for the first 15 m in of recovery. 3. The results showed no measurable effect of creatine supplementation on respiratory gas exchange and blood lactate concent rations during either incremental submaximal exercise or recovery, Thi s suggests that creatine supplementation does not influence substrate utilization during and after this type of exercise.